Hang on. I take that back. It was coincidence that the surrogate field had the same value as its "parent" field. The value of the surrogate field has nothing to do with anything and is always "1", no matter what the value of the actual field. So, I guess, the value for the surrogate could well be "foo". All that matters is that it was there in the first place, which tells Domino its parent was too. If not parent field is posted back we know it's had all values unticked.
Hang on. I take that back. It was coincidence that the surrogate field had the same value as its "parent" field. The value of the surrogate field has nothing to do with anything and is always "1", no matter what the value of the actual field. So, I guess, the value for the surrogate could well be "foo". All that matters is that it was there in the first place, which tells Domino its parent was too. If not parent field is posted back we know it's had all values unticked.